Turning off PCs during periods of inactivity can save companies a substantial sum. In fact, Energy Star estimates organizations can save from $25 to $75 per PC per year with PC power management. Those savings can add up quickly. According to a recent report by Forrester titled "How Much Money Are Your Idle PCs Wasting?" PC power management is helping General Electric and Dell boast savings of $2.5 million and $1.8 million per year, respectively. That also results in a substantial reduction in CO2 emissions.

So why is there hesitancy at some organizations to implement PC power management, given that the payback is easy to calculate? Perhaps some companies are being swayed by myths about PC power management. Forrester outlines five such myths in its report.

Myth No. 1: The power used turning my PC on negates any benefits of turning it off. Forrester debunks this myth as follows: The average desktop draws 89 watts per hour. If it's left on overnight for 16 hours, it consumes 1.42kW. It's impossible for the power surge that occurs when powering on a PC to rival that figure: "You would be drawing energy at a rate of 17 kWh -- the equivalent of 44 HP DL580 servers at 100 percent utilization. Moreover, the average US wall outlet can only provide 1.8 kW of draw, which is about one-tenth of what the power surge would require."

Myth No. 2: My screen saver is saving me energy. Though at times entertaining and whimsical, screen savers aren't power savers. As the report notes, "Certain graphics-intensive screen savers can cause the computer to burn twice as much energy," according to the EPA's Energy Star Program. A screen saver displaying moving images consumes just as much electricity as an active PC. A blank screen saver is slightly better, but most screen savers don't save energy unless they actually turn off the screen, or in the case of laptops, turn off the backlight. In short, it's better to place PCs in a lower power state than it is to run a screen saver.

Myth No. 3: Turning my PC on and off will reduce its performance and useful life. There may have been some truth to this once upon a time, the report notes, but today's new and improved modern hardware can handle it. The Forrester Report cites findings from the Rocky Mountain Institute: "Modern computers are designed to handle 40,000 on/off cycles before failure, and you're not likely to approach that number during the average computer's five to seven year life span. In fact, IBM and Hewlett Packard encourage their own employees to turn off idle computers, and some studies indicate it would require on/off cycling every five minutes to harm the hard drive."

The report goes on to say that "powering down your computer may actually extend its life cycle by reducing the intake of dust, which can cause fans to seize up or parts of circuit boards to overheat."[ Powering up and down PCs is OK -- but find out why powering down servers is a calculated risk. ]

Myth No. 4: I can't run updates and patches for PCs in lower-power states. It's perfectly possible to rouse PCs from slumber for patches, updates, and backups. "This is most often achieved using WOL (Wake on LAN) technology -- an Ethernet networking standard that allows PCs to be 'woken up' from a lower power state after receiving a 'magic packet' network message. Alternatively, recent hardware improvements such as Intel vPro can offer similar functionality without relying on the WOL standard," according to the report.

Myth No. 5: My PC users will not tolerate any downtime for power management. The Forrester report does acknowledge that end-users have very little patience for downtime. However, it suggests that "potential user complaints can be mitigated by communicating the positive financial and environmental benefits of PC power management."